Answer:
The interval notation is;
![(-\infty,4]](https://img.qammunity.org/2020/formulas/mathematics/high-school/vii5ydp4fz8c6ap6xlw448p0sh9j2u4iw4.png)
Explanation:
The solution set of the inequality represented on the number line is

The boundary 4 is inclusive in the solution set, so we use square bracket "[ ]" to show inclusion and open bracket "()" to show that, that part of the interval in not bounded.
In interval notation, we can write this as;
![(-\infty,4]](https://img.qammunity.org/2020/formulas/mathematics/high-school/vii5ydp4fz8c6ap6xlw448p0sh9j2u4iw4.png)
Repeated